In medical implements needing connection of flow paths for liquids used in infusion, transfusion, nutrition dosing or the like, it is necessary to perform, as required, connection/disconnection of liquid flow paths (circuits) at the time of effecting sustained or momentary flow of a liquid such as a medicinal liquid, blood, fluid food, etc. In such an instance, it is known to attach a connector for connection between liquid flow paths to an intermediate part of a circuit.
Representative examples of such a connector include a three-way cock (connector) (see, for example, Patent Document 1). The connector described in Patent Document 1 has a connector body (base) having an inner cavity part (recessed part), and three tubular connection sections formed to project from the connector body. Valve bodies are disposed respectively in two of the three connection sections. In a connector having such a configuration, the two connection sections in which the valve bodies are disposed are referred to as “female-side connection sections,” while the remaining connection section is referred to as a “male-side connection section.” Each of the female-side connection sections is configured such that a tube body (for example, a tube or a mouth part of a syringe) can be connected thereto, and a valve body is opened or closed according to whether the tube body is connected or not connected.
In order to configure an infusion circuit by use of the connector according to Patent Document 1, an infusion bag and a tube are prepared separately, one end side of the tube is connected to the infusion bag, and the other end side of the tube is connected to, for example, one of the two female-side connection sections of the connector. As a result, an infusion circuit is configured. When the infusion circuit is used, for example, a gas-permeable cap may preliminarily be attached to (put on) the male-side connection section of the connector, whereby air in the tube and the connector can be replaced by an infusion, or priming can be performed, before use of the infusion circuit. This results in a condition in which the entire inside space of the connector, namely, the inside of the connector body and the inside of the connection sections, are filled with the infusion.
When the cap is detached in this condition, however, liquid at the inside may leak or scatter from the male-side connection section, depending on the tension between the cap and the infusion, or the internal pressure in the connector.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2005-137407